Path Of The Iron Fist

Most people are comfortable putting their combative abilities into a sword, an axe, or even a bow and arrow. However, some brave warriors chose to forgo traditional weapons in favor of their fists. Barbarians who follow the Path of the Pugilist enhance their body's natural weapons to the point where they can shake the ground they stand on with their bare hands.

Fist Of Fury

Starting when you choose this path at 3rd level, your unarmed strikes deal bludgeoning damage equal to 1d6 + your strength modifier on a hit. This damage increases to 1d8 at 6th level, 1d10 at 10th level, and 1d12 damage at 14th level. Additionally, when you use the attack action with an unarmed strike on your turn, you can make one unarmed strike as a bonus action.

Additionally, at the start of each of your turns, you can deal 1d4 bludgeoning damage to one creature grappled by you. This damage increases to 1d6 at 6th level, 1d8 at 10th level, and 1d10 at 14th level.

Counter Punch

Also at 3rd level, you have learned to take advantage of your enemy's mistakes. When an enemy creature misses a melee attack against you, you can use your reaction to make an unarmed strike against that creature.

Brawlers Onslaught

You’ve become so accustomed to hand-to-hand combat that your rage and fury take over when you fight. When you use a bonus action to rage you can choose to go into a Brawlers Onslaught. Entering this state hardens your arms like steel, making your unarmed strikes deal force damage. You also gain an additional +2 armor, and your rage damage increases by half your proficiency rounded down.
As a result of this Onslaught, when your rage ends you suffer one level of exhaustion. 

Potent Knuckles

Starting at 6th level, your unarmed strikes count as magical for the purpose of overcoming resistance and immunity to non-magical attacks and damage.

Durable And Versatile

Thanks to your knowledge and experience of combat you’ve gained additional durability. When you enter a rage, you gain temporary hit points equal to your proficiency + Strength modifier + Constitution modifier. These temporary hit points last until you finish your rage. 

In addition, you also gain proficiency with improvised weapons due to your use of close-quarters combat. 

Tremor Punch

At 14th level, your punches can shake the ground you stand on. While you’re raging, you can use an action to punch the ground, creating a shockwave around you. Each creature on the ground within 30ft of you must make a Dexterity saving throw (DC = 8 + your proficiency bonus + plus your strength modifier). On a failed save, the creature is knocked prone. Additionally, the ground within 30ft of you becomes difficult terrain until the beginning of your turn. 

If you use this on top of a creature, it must make a Strength saving throw (DC = 8 + proficiency bonus + Strength modifier). On a failed save the creature takes 10d6 Bludgeoning damage and is knocked prone. On a successful save, it takes half as much damage and isn’t knocked prone. This attack deals double damage to structures. In addition, if you are in a Brawlers Onslaught, the damage becomes Force instead. 

Once you use this trait, you cannot use this again until you finish a long rest.